It's been a while due to work and other projects taking my time but thought I'd add a brief update. I completed a circuit using the touch sensor and made my own micro USB input and standard female USB output. The input is for a standard 5v power source from any USB charger/PC and the output is used to charge a device externally as a passthrough. As well as a cabled output I also fitted the QI wireless charge circuit so I can charge enabled devices without cables.
Whilst the circuit works exactly as planned, I wasn't happy about the separate USB ports because of both durability and mounting so was looking at having custom double-sided circuits made up.
However, I've just picked up a standard USB power bank designed to be used with 18650 cells that are the lipo cells used in laptop batteries. The benefit of this is the tiny double-sided circuit board that contains a micro USB input, female USB output and a lipo charge & boost circuit for less than a couple of £!
I've stripped an old laptop battery which has provided 4 x 2000mah cells which will power the LEDs for longer without adding loads of weight. As a result I'm now looking at making the desk mount lightblock with lipo power built in. The desk mount unit can be run from an external power source if available but it can then also be taken off the desk to be used as a nightlight and external power bank.
This is one 18650 cell (a little bit bigger than a AA battery) and the tiny double sided circuit next to it;
I've also spent some time reading up on the touch sensor circuit and have found out that if I add various strength capacitors I can increase the sensing range. I've ordered some small ceramic caps in the size that should give a 3-6mm sensing range meaning that I should be able to move my finger above the block and turn it on/off then hold it in place to adjust the brightness. I should get them in the post tomorrow so I'll see how well that works.
I'm trying to get a unit built using a deep single gang back box for a plug socket to give me an almost cube lightblock. If I can get it together this week I'll bring it along to the lakes meet.
Cheers
Steve